A Long Term Evolution-Advanced (“LTE-A” for short) system is an evolution and enhancement to a 3rd Generation Partnership Project (“3GPP” for short) Long Term Evolution (“LTE” for short) system. A carrier aggregation (“CA” for short) technology, also known as a spectrum aggregation technology or a bandwidth extension technology, is introduced in the LTE-A system, to ensure that a peak data rate provided by a fourth generation communications technology can satisfy requirements of the International Telecommunication Union. In carrier aggregation, spectrums of two or more component carriers are aggregated to achieve wider transmission bandwidth, where the spectrums of the component carriers may be contiguous continuous spectrums, or may be non-contiguous spectrums within a same frequency band or even discontinuous spectrums in different frequency bands. An LTE Rel-8/9 user equipment (“UE” for short) can access only one of the component carriers to receive and send data; whereas, an LTE-A user equipment can simultaneously access multiple component carriers according to its capability and service requirement to receive and send data.
To support technologies such as dynamic scheduling, downlink multiple input multiple output (“MIMO” for short) transmission, and hybrid automatic repeat request, a terminal needs to feed back multiple types of uplink control information (“UCI” for short), including channel state information (“CSI” for short), hybrid automatic repeat request (“HARQ” for short) information, a scheduling request (“SR” for short), and the like, to a base station through a physical uplink control channel (“PUCCH” for short) and a physical uplink shared channel (“PUSCH” for short), where the hybrid automatic repeat request information may be simply called acknowledgment (“ACK” for short)/negative acknowledgment (“NACK” for short), or the hybrid automatic repeat request information may be called hybrid automatic repeat request acknowledgment HARQ-ACK.
However, in a CA system between base stations, because data scheduling of multiple downlink carriers is independently performed by each base station, which means that uplink control information (“UCI” for short) of each carrier is separately fed back to a base station of each carrier. In which case, a UE may have to transmit UCI on multiple carriers, for example, multiple PUCCHs are simultaneously transmitted or multiple PUSCHs carrying UCI are transmitted. Total transmit power of all to-be-transmitted uplink channels and/or sounding reference signals (“SRS” for short) exceeds maximum transmit power of the user equipment, and consequently, the user equipment cannot send information properly.